Q131 / 150 · MHT CET 2023 (09 May Shift 2) · Physics
Two coils A and B have mutual inductance 0.008 $\mathrm{H}$. The current changes in the coil $\mathrm{A}$, according to the equation $\mathrm{I}=\mathrm{I}_{\mathrm{m}} \sin \omega \mathrm{t}$, where $I_m=5 A$ and $\omega=200 \pi \mathrm{rad} \mathrm{s}^{-1}$. The maximum value of the e.m.f. induced in the coil B in volt is
- A$4 \pi$
- Correct answerB$8 \pi$
- C$10 \pi$
- D$16 \pi$
Solution
$\mathrm{e}=\mathrm{M} \frac{\mathrm{dI}}{\mathrm{dt}}$
Given: $\mathrm{M}=0.008, \mathrm{I}_{\mathrm{m}}=5 \mathrm{~A}, \omega=200 \mathrm{rad} / \mathrm{s}$ $\therefore \quad \mathrm{e}=0.008 \times \mathrm{I}_{\mathrm{m}} \omega \mathrm{e} \mathrm{os} \omega \mathrm{t}$
For $\mathrm{e}=\mathrm{e}_{\max }, \cos \omega \mathrm{t}=1$
$\begin{aligned}
\therefore \quad \mathrm{e}_{\max } & =0.008 \times \mathrm{I}_{\mathrm{m}} \times \omega \\
& =0.008 \times 5 \times 200 \pi \\
& =8 \pi
\end{aligned}$
Hence, the correct answer is option: 'B'.